1. Field of the Invention
This invention relates generally to the field of hydrotherapy apparatus and methods, and specifically to an apparatus and method for preventing hypovolemic shock to a human body as a result of being immersed in hot water.
2. Brief Description of the Prior Art
The use of spas and pools that circulate heated water to provide hydrotherapy or general relaxation to the human body has increased over the past years. One of the earlier designs is shown in Van Horn, "Hydrotherapy Tank," U.S. Pat. No. 4,090,507. Van Horn describes an apparatus that spirals water solely around the lower portions of the lower extremities of the human body. The lower extremities are required to be in an elevated position. Similarly, Alenares. "Hydrotherapy Apparatus and Method for Exercising the Veins of the Leg and Foot," U.S. Pat. No. 4,099,522 shows apparatus that directs water specifically to the feet and calf portions of the lower extremities while the lower extremities remain horizontal in a collecting pan.
More recently, Mandell, "Reciprocating Hydro-Message Apparatus,38 U.S. Pat. No. 4,339,833 suggests use of a tub suitable for a human body to be seated therein and almost completely submerged in water. An apparatus is provided for reciprocating nozzles that emit water solely to the backside of the upper torso. In a somewhat similar fashion, Starkey, "Hydrothermal Treatment Facility," U.S. Pat. No. 4,466,141 depicts a vessel in which a human body can be supported in various positions while almost completely submerged in water. Jets emit water to contact the various joints of the body.
One problem encountered by persons who use spas and pools, particularly like those shown in Mandell and Starkey, is that increased body heat is produced which, in turn, may result in hypovolemic shock. The circulatory system in the human body attempts to correct the increase in body heat by dilating the superficial arteries and veins of the skin. The flushing of blood to the skin necessarily drains blood away from the large central arteries and veins of the circulatory system.
In normal activities, the muscle and skeletal systems assist in pumping the blood back towards the heart. However, in the hot water of a spa or pool where there is little or no physical activity by the human hody, the combination of inactivity and flushing of blood to the surface of the skin removes a large volume of blood from the central circulatory system. This could result in the heart contracting on an empty chamber. Should this occur, blood pressure will drop precipitously, the human body may become suddenly weak and lapse into unconsciousness or suffer a heart attack.